Crushed coral or activated carbon, or both?

[rpmsongs]

I've been reading for hours and hours. Articles and forum posts. So, my ph is pretty low, so low that after having done 25% water changes for 5 days, where my tap water has a ph of 7.9 and a kh of 2 dkh, my aquarium water's ph is below 6 and kh is below 1. What the hell? I've got a good amount of plants and I've been trying to figure out what metals are removed by the carbon, and what negative side effects there are to crushed coral if any, wheter to put it in my filter, or as a substrate etc... And there's so much to read, and I'm not a chemist, and this is a situation, and I don't have time to go to college just to keep a planted aquairum. Someone please just throw some wisdom at me. My fish and I would all be happier with a more alkaline environment.

 

[blazingazn]

sounds like something in your aquarium is reacting with the water and making it acidic. did you pick up any rocks from the outside and placed it into your aquarium? i had that problem once. i discovered that a rock i had was just bringing the pH down

 

[rpmsongs]

All the rocks I have have been in the tank for ages. But it's possible. I don't remember where I got the rocks. I have some new slate, but I thought that helps buffer, but again, i'm not a chemist.

So, I just got a test kit for phosphates. It's 2.0 ppm. and my tap water's only .25 ppm. So, there's definitely something wrong, It could also be the black rocks I bought at the LFS, I'll try to test outside the tank. In the meantime...

I've been reading about removing the phosphates and one poster said he put one of the phosphate removing pads in his tank and the ph swing killed his fish almost over night. so...

Is there s a safe way to remove these phosphates?

 

[KarlTh]

With that KH the high pH of the incoming water will not be stable and will soon fall, as you're discovering. Raise the KH - bicarb of soda is the simplest - and the problem will go away. Not that the fish care anyway.

pH swings do not kill fish, unless you're talking about 6-8 in half an hour or so. The phosphate removal did something else which caused the mortality.

 

[tanker]

What kind of fishes do you have?? Cardinals, Neons, Discus would love that water.

 

[rpmsongs]

piranhas and guppies.

 

[tanker]

Piranhas would like that kind of water----And the guppies can adapt to it.

 

[Jspigs]

Piranhas would like that kind of water----And the guppies can adapt to it.

:iagree:

 

[Piranha86]

Are the guppies in there for food?

 

[Dr. Awkward]

Sounds like old tank syndrome to me. It can happen fast to tanks with messy fish. I'm guessing you don't siphon the gravel because of the plants?